Some prior art engine valvetrains are selectively adjustable to vary the amount of valve travel during opening. Typically, such valvetrains are selectively adjustable between a low-lift mode, in which the valvetrain causes an engine poppet valve to open a first predetermined maximum amount (with lost motion), and a high-lift mode, in which the valvetrain causes the poppet valve to open a second predetermined maximum amount that is greater than the first predetermined maximum amount. This adjustability is accomplished with the use of a two-step rocker arm assembly. Prior art two-step rocker arm assemblies typically include an inner and an outer rocker arm assembly operating in contact with a camshaft having two distinct cam profiles, a low-lift cam and a high-lift cam.